What builds an endurance athlete, be it in IRONMAN Triathlon races or Spartan Obstacle Course Races?

Would the dirt, mud and grit of obstacle course racing (OCR) prepare you better for gruelling mental and physical challenges of a 3.9km swim, 180km bike and 42km run in triathlon, or vice versa?

IRONMAN talked to a handful of athletes with experience racing both types of events and compiled 5 top reasons why going from climb-lift-crawl to swim-bike-run satiates the hunger of endurance athletes.

1. You have the hunger
   

   “To be a great IRONMAN athlete or a great Spartan athlete, you just have to have grit. You have to be willing to push yourself to the limit,” says Heather Gollnick, former pro triathlete and five-time IRONMAN champion.

   Gollnick is now a member of the Spartan Professional Racing Team and coaches athletes in both sports.

   “I see IRONMAN athletes that are getting into Spartan, and I see a lot of athletes that have been doing Spartan racing for three or four years, and now they want to try a half or full IRONMAN,” says Gollnick.

   

2. You’re drawn to the “impossible”
   

   Ron Searle started doing Warrior Dash races before Spartan and other similar races were even a thing. The 46-year-old got his endurance racing start in short-course triathlon, then took on OCR before ultimately making the leap to IRONMAN.

   For Searle, the impetus for both was the challenge, and the desire to push himself “to do things I never thought a fat guy could ever do.”

3.  You have the confidence
   

   “When I decided to attack the 140.6 mile (IRONMAN) distance, I took this newfound confidence and harnessed it into motivation,” continues Searle, who tackled IRONMAN Coeur D’Alene in 2011 and IRONMAN Wisconsin in 2015.

   “Being a big guy, 140.6 was hugely intimidating. The Warrior Dash really helped give me the confidence.”

   

4.  You stand out from the crowd
   

   “Insanity. Is that one of the requirements for both sports?” jokes John Post, a 69-year-old, six-time Kona finisher who now enjoys obstacle racing.

   For Post, a retired doctor who opines the common threads between OCR and IRONMAN include the sense of joy and accomplishment after finishing, and the feeling that you’re doing something different than the average Joe. 

5.  You’re accustomed to cross-training
   

   Fifty-year-old Mark James raced triathlon from 1985 to 2005, competing in Kona from 1991 to 2001 before taking a decade off to raise kids, work two jobs, and work on a house. Then he got into OCR, and realized that both sports require a certain amount of cross-training.

   “The training is somewhat similar, although now I seldom ride and I swim only two days or so a week. My runs are in sand or on trails from 3 to 12 milers, and I spend a lot of time on the obstacle course we have at SEAL training where I live in Coronado [California]. I climb a bit, too, and focus on OCR-type workouts—pull ups, crawls, cargo net climbing, etc.”

   

Gollnick, however, does have one note of warning to Spartan athletes considering the IRONMAN challenge: triathletes can be a little, shall we say, detail-obsessed.

“In triathlon, everything is exact. The distances are precise. People get bent out of shape if a 6.2-mile run is 6.3 or 6.1,” she says.

“Obstacle racing is so different because it’s on the trails and through mud and creeks and water, so everything is ‘ish.’ A Spartan Sprint is 4-5-ish, a Super is 8-10-ish, a Beast is 13-16-ish, and an Ultra Beast is somewhere around a marathon.”

So, if you’re a persistent, confident, sweat-loving, cross-training exercise junkie who can handle a bit of the Type-A tendency to stick to strictly prescribed distances—you’ve already got a leg up, physically and mentally, in the journey to IRONMAN.

Read more on Ironman.com